New Himalayan Bird Species Has Unique Tune, Researchers Say

A new species of bird was recently found hidden among the snow-capped mountains of the Himalayas in northern India and China and it can carry a tune better than its closest relatives, researchers report in a recent study.

"There aren't too many new birds to be found in the world," lead author Per Alström, of Uppsala University, told the BBC. "So it's exciting when you find one."

Researchers from Sweden, China, the U.S., India and Russia have been studying this bird, subsequently dubbed the Himalayan Forest Thrush (Zoothera salimalii), since 2009. That's when they first suspected that it was a separate species from the Plain-backed Thrush (Zoothera mollissima), another small bird that lives in northeastern India.

The first thing that caught researchers' attention was the fact that the Plain-backed Thrushes' in the mountain's coniferous and mixed forest had a rather musical song, which differed from that produced by thrushes living on bare rocky ground above the tree line in the same area. The rocky peak-dwellers had a much harsher, scratchier, more "unmusical" song, according to a news release.

"They had – to us – incredibly different songs. We couldn't at first find any differences in plumage or structure between them. But we didn't actually see the forest one very well because it was extremely elusive, extremely hard to see," Professor Alström added.

Researchers have since spent years studying song recordings of each bird, analyzing duration, mean frequency and frequency bandwidth. The team also compared wild birds from India and China with specimens from 15 museums around the world.

Then, after performing a DNA analysis, researchers confirmed what they had thought all along: The two birds living in different areas and singing different songs have been breeding separately for millions of years. The scratchier singers have since been named the Alpine Thrush, though they retained the "original" scientific name, Zoothera mollissima.

Researchers suspect the birds began as a single species and then evolved into two distinct populations to cope with their very different habitats. For example, the Himalayan forest thrush has shorter legs and a shorter tail, since longer legs are better suited for open environments.

However, while on their trips to neighboring parts of China, researchers stumbled upon another Thrush population – previously considered a sub-species of Plain-backed Thrush – that may also deserve its own classification. This bird, subsequently named Sichuan Forest Thrush (Zoothera griseiceps) is also physically and genetically distinct, with a song that is even more musical than its relatives in the Himalayan forest, researchers say.

The Himalayan forest thrush is only the fourth species of bird discovered in India since the country achieved its independence in 1947. The study was recently published in the journal Avian Research.